Google-fu didn't show up any ISSKA, WMTA.
It did turn up the ISKA, but no cross-hit w/ his name
The WKBA does exist, but the only references I could find online that included his name were by him/school website.

Ronin went on to become a champion kickboxer in three different organizations after traveling to Europe and studding under the Johan Vas school which is one of the best kickboxing systems to date. Ronin had the honer to be trained by K-1 champion Andy Hug ( RIP) and was parted by Andy's death.

also:

by age 14 Ronin was a black belt in Shotokan karate and a brown belt in kodokan Judo

That is where I train now and I have heard some of the fighters talk about Americans coming in, having one shitty amateur fight and then going back home and sell Dutch Kickboxing lineage for $100 per private to hold pads. Americans selling Dutch kickboxing lineage is pretty big apparently. Not rumors, but my friends I train with now, tell me about this sort of thing happening to guys they trained/trained with.